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4 Sheets-Sheet 1.

' (No Model.)

' T. B. SLOPER. ELECTRIC TELEPHONIO SWITCH AND SYSTEM.

Patented Dec. 27,1892.

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{No Model.)

.T. B. SLOPER.

ELECTRIC TBLEPHONIG SWITCH AND SYSTEM.

Patented Dem 27, 1892.

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(No Model.) 4 SheetsSheet 3.

T. B. SL-OPER. ELECTRIC TELBPHONIC SWITCH AND SYSTEM.

No. 488,666. Patented D90. 27, [892.

4 Sheets-Sheet 4.

(No Model.)

T. B. SLOPER. ELECTRIC TBLBPHONIG' SWITCH AND "SYSTEM. No. 488,666.

Patented Dec. 27,1892.

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' Nrrnn. STATES ATENT FFICE THOMAS BEAVAN SLOPER, OF D EVIZES, ENGLAND.

ELECTRIC TELEPHONIC SWITCH AND SYSTEM.

SPECIFICATION forming part of Letters Patent No. 488,666, dated December27, 1892.

Application filed May 18, 1892. Serial No. 433,473. (No model.)

To all whom it may concern.-

Be it known that I, THOMAS BEAVAN SLOPER, a subject of the Queen ofEngland, residing at Devizes, in England, have invented certain new anduseful Improvements in Electric Telephonic Switches and Systems, ofwhich the following is a specification.

This invention relates to electric telephonic switches and the systemknown as the intercommunication system, of workingthem, the arrangementbeing such that any two lines of the whole system, which mayinclude anydesired number of instruments may be connected directly with each otherwithout an intermediate station and if desired the talking effectedthrough the wires of the instruments of both stations.

The invention will be best understood by reference to the accompanyingdrawings in which Figures 1 and 2 are respectively afront and backelevation of one form of the switch adjusted as when ready forringing-up No. 6 station. Fig. 3 is one half of a back elevation showingthe switch as when it has received a call and is being talked through.Fig. 4 is a section taken on line 4:'4: of Fig. 2. Figs. 5 and 6 aresections taken-on line 56 of Fig. 2, Fig. 5 showing the switch as whenadjusted for ringing-up N0. 6 station, and Fig. 6 as when suchringing-up is in operation. Figs. 7 and S are similar half-backelevations of a switch constructed on the same principle as that shownin Figs. 1 to 6 but in addition provided with a switch or bridge forcutting off the earth or return wire altogether from the twocommunicating stations and connecting them in such a manner that thecurrents between the two stations pass by one wire and return by theother thus isolating the two instruments being conversed through fromall the others of the series, Fig. 7 representing the switch in itsnormal position and Fig. 8 as when it has been rung-up and adjusted forprivateconversation with station No. 6 by the person at the called-upstation. Figs. 9 and 10 are views showing the two diftferent positionsof the additional switch or bridge for forming the secret circuit. Fig.1O is a section drawnto a smaller scale than Figs. 1 to 10showing theswitch arranged with the hook arm in the form of a three-armed lever.

Figs. 11 and 11 are diagrams showing an installation of six stationsprovided with the switch shown in Figs. 1 to 6 and Figs. 12 and 12 aresimilar diagrams showing an installation ot'six stations provided withthe switch shown in Figs. 7 to 10.

Like letters andfigures indicate like throughout the drawings.

Throughout this specification and in the accompanying drawings each ofthe switches is described and illustrated as adapted for'an installationof six instruments but it will readily be understood from the followingdescription that by increasing or decreasing the number of contacts theswitch may be constructed for an installation of a larger or smallernumberof instruments.

Referring to Figs. 1 to 6, A is a preferably circular block or plate ofwood, vulcanite or other suitable material recessed at its back toreceive the various contact devices and perforated and preferablymetal-hushed at its center to admitof the spindle B being movedlongitudinally and rotarily therein. On the outer end 0t the spindle Bare secured a head or press-button B an index or pointer B and parts acrank handle B which may be formed in part with the pointer B and on theouter face of the block A are depicted numbers A or other denominatingsymbols corresponding to the several stations in the installation lessthat of the instrument itself which may advantageously be moreboldly-depicted as at A The pointer B may be turned by the handle B toany of the numbers A as also to a plate bearing the word Reply or othersymbol A Fig. 1 to which it should though not compulsorily be directedwhen the instrument is not in use.

G C C O C and O are six contact plates to five of which are fittedcontact springs each for convenience marked with a corresponding smallletter such as c c &c. and all when hereinafter collectively mentionedbeing referred to as the contact springs 0' (inc; the index numerals ofthese large and small reference letters in this description serve alsoto identify the various contacts with the different instruments oftheinstallation. the six contact plates 0' C C G O and O as also thecontact plates DF and G are provided with binding screws 0 forconnecting Each of the various conductors to them as hereinafterexplained.

B is a metal disk secured by a screw B on a squared or equivalentlyshaped part of the spindle B and which is provided with an arm .orprojection B adapted to make electrical contact with the inner ends ofthe springs c or c &c.; the arm or projection B instead of being formedin part with the disk B may be integral with the spindle B.

H is a spring which bears upon the headsof screw B so as to tend alwaysto press the spindie 13 outward and the disk 13 against the contact I asshown in Fig. 4 and returns said parts to said respective positionsafter having been pressed inward as shown in Fig. 6 by a personringingup another station and in which inner position the contactbetween B The spring H does not act 1 as an electrical conductor; ifdesireda helical spring encircling the spindle B may be suband I isbroken.

stituted for the spring H.

1 J is the hook arm upon the outer-or hooked 2 end of which asordinarily the receiver K is hung as shown in Figs. 1 and 2 and which ispivoted at J and which a spring J 2 attached thereto always tends todraw to the position shown in Fig. 3.

F is a contact spring upon which the arm J bears when held down by theweight of the receiver K, and G and L are two other contact springs thelatter of which is connected by wire L with the contact I and both ofwhich are normally, that is, when the arms J is in its lowered position,out of contact with each other and with the hook arm J asshown in Fig. 2but which, when the receiverKis re- 1 moved and the spring J allowed toraise the arm J, are pressed into electrical contact both with eachother and with the arm J as shown in Fig. 3.

The contact plate C is electrically connected by a wire 0 and throughthe pivot J v with the hook arm J, and the contact plateD which ashereinafter explained is connected to the local battery is provided witha metal blade D which as shown in Fig. 5 is out of cont-act with thedisk 13 when said disk is pressed forward by the spring H but with whichthe disk B makes electrical contact when it is pushed back by' theoperator for calling-up a distant station.

The inn er end of each of the contact springs c &c. is preferablyprovided with a rib or projection c as shown clearly in Figs. 5 and 6and the arm B is also provided with .a groove B for receiving thisprojection 0 so that it may readily be felt by the resistancetofurnections which are altered to suit this addition.

In Figs. 7 and 8 M M represent a bell-crank lever pivoted at M and isconstructed preferably of insulating material such as vulcanite and tothe arm M of which is secured ametal plate M The arm M like the hook armJ projects through a slot in the block A to the outside of said blockand is so arranged that after the receiver K has been removed from off Jand the lever arm M has been raised by hand from the position shown inFig. 7 to that shown in Fig. 8 the said lever arm M will be moved to itsoriginal position (Fig. 7) whenever the receiver K is again hung on armJ. N N are two contact springs the free ends of which are normally incontact with two plates 0 0 respectively. The contact springs NN asshown clearly in Figs. 9 and lO-a-re bent so as to allow themetal-plate-carrying-leverarm M to work beneath them and while in theposition shown in Figs. 7 and 9 to be out of contact with them and allowthem to rest in contact with the plates 0 O, and so that when the leverM M is moved to the position shown in Fig. 8 the arm M will raise thesprings N N out of contact with plates 0 O and make electrical contactbetween them spring N, and conductor 0 leading from N to C the circuitthrough these conductors being broken as soon as. the spring N is raisedoit plate 0. The plate 0' is connected with a plate E by wire 0 and thecontact spring N is connected by a wire 0 with-a platePwhich like theother similar plates before described is provided with a binding screw0.

In Fig. 10 the hook arm upon which the telephone receiver K may be hungis pivoted in the plate A so as to project out through the front of itand is in the form of a three-armed lever, the arm J having the hookformed upon it, the arm J being caused by the spring J to make contactwith the contact plate or spring G" connected with the telephoneappertaining to the instrument in question, or, when the weight of thetelephone receiver K upon the hook overcomes the spring .J the arm J asshown in Fig. 10, makes contact with the contact plate or spring Fconnected with the bell appertaining to the same instrument. The thirdarm I L (referred to by these two letters because it fulfills thefunctions of the before described contacts I and L; is adapted to movethe disk B longitudinally upon its axis so that its contact projection Bwill be in the proper plane to make contact with any one of the contactplates 0 &c. of the respective line wires of the system, when thereceiver K is ofi the hook. By means of the same arm I L or of thespring H similar ITO to that before described and shown in Figs. 2 to 8when the telephone receiver K is upon the hook,,the disk B is so movedthat its contact projection B is clear of all the other contact platesor springs c &c. but so soon as the weight of the receiver K is removedthe disk B moves forward projecting the arm B into the plane of theplates or springs c. In addition to the radial contact plates or springsc &c. there is also provided the metal blade D with which as in thebefore described examples, the disk B can be brought into contact whenpushed in for the purpose; this contact is in direct connection with thebattery.

appertaining to the station and through it the battery current can becarried to any of the wires of the system in order to ring the bell at adistant station.

Referring now to Fig. 11, which diagrammatically represents aninstallation of six telephone stations numbered from 1 to 6 and eachprovided with a switch similar to that shown in Figs. 1 to 6, it will beseen that all the contactsprings cexcept at No. 1 station where suchspring is not necessary are connected together by conductor P and thatthis conductor is connected through plate 0 and Wire 0 with hook-armpivot J of said No. 1 station and constitutes the home line of said No.1 station. Similarly all the contact springs 0 except at No.2 stationwhere it is not necessary are connected together by conductor Pconstituting the home line of station No. 2, and which is connected,through plate 0 with pivot J as shown clearly in Figs. 1 and 2 whichrepresents this No. 2 switch. All the contact springs 0 except at No. 3station where one is not necessary are connected together by conductor Pconstituting the home line of station No. 3, and which is connectedthrough plate 0 with pivot J of No. 3 station, and so on throughout theseries of switches. Each of the contact plates F is connected by a wireF with one terminal of the coils of a call bell Q, Q Q Q Q or Q theother terminal being connected by a wire Q to earth said wiresconstituting the bell line of each station. Each of the plates G isconnected by a wire R to one terminal of the appropriate telephone R, RR R R or R the other terminal of which is connected through wire S toearth constituting the tele-.

phone line of each station. Each of the blades D is connected by a wireT to one pole of a local battery T T T T T or T the other pole of whichis connected to earth by a wire T The operation of, the installationshown in Fig. Fig. 11 is as follows:Supposing the operator at No. 1station requires to call-up No. 3 station he first turns round the indexB until it points to the number three (A') so as to bring the arm B intocontact with c the terminal of the home line of station No. 3 and thenpresses the button B so that the disk B bears against the blade D. Thecurrent from battery T now passes through the blade D disk B and contactspring-c of No.1 station along wire 1? to No.3 station where it beingcompleted through wires Qof No.3 station, earth and Tiof No. 1 station.In this manner the bell Q will be sounded and all the operator at thecalled-up station (No. 3) has to do is to take the receiver K offhookarm J at that station and preferably place the index B at Reply asshown with regard to the arm B in Fig. 3 when he can talk through thetelephone as usual. This operation at No. 3 station. by allowing thehook arm J to be raised by its spring J out of contact with spring Fbreaks the circuit through the bell Q The operator at No. 1 station byremovin g the pressure of his hand from the knob B y at that stationallows the spindle -B to be returned by its spring H to its normalposition when the contact with blade D and consequent circuit throughthe battery T will be broken; he then removes his receiver K from thehook arm J at his (the No. 1') station so that by the ascent of the hookarm J out of contact with spring F the circuit through the bell Q isbroken and the telephone circuit between the two instruments R and R iscompleted in the following manner:-One terminal of each of thetelephones R, R is connected to earth by one of the wires S and assumingthe current through the switches to pass from station No. 1 to station"No. 3it will leave the telephone R byway of the appropriate wire R passto switch of N o. 1 station through plate G and the spring contacts Gand L which are then pressed together by hook arm J, contact I disk Bdisk-arm E contact c and leave station No.1 through the wire P whichconducts the current tothe plate 0 of No. 3 station. The current thenpasses through wire 0 to pivot J and through hookarm J, contact G'plateG and wire R to the telephone R If when the operators at say theNo. 1 and No. 3 stations are speaking the arm B at No. 1 station be incontact with the spring 0 as before described and the arm 1? at No. 3station be in contact with spring 0' then the currents will pass betweenthe two instruments partly through the home line wire P of station No. land partly through the home line wire l? of station No. 3 returningthrough earth, the hook arm J of No. 1 instrument being thenelectrically connected with No. 3 switch and the hook arm J of No. 3connected with No. 1 switch. 1

- With the last described system andbecause one terminal of each of thetelephones'is connected to earth it is possible for the conversationbetween two stations, say Nos. 1 and 3 as before, to be heard throughtheinstrument of a third station by the operatorat thatthird station sayNo. 2 turning the arm ]3 until it makes contact through one of thesprings in this example either 0' or c with one. of the' wires P or Pthrough which the telephonic currents pass. It is to overcome this thatI devised the system illustrated in Figs. 7, 8, 9, 10 and 12 and whichIcall the secret circuit system and by which any two stations of theseries may be completely out out of communication with the others. Inthis system as shown in Fig.12 the bell-circuit is completed and brokenin precisely the same way as in the arrangement shown in Fig. 11. Noneof the telephones R &c. are however directly connected with earth, thecomplete metallic circuit being established over the home lines of therespective stations between which the conversation is taking place, thehome line of one station being the positive and the home line of theother station the negative wire.

Supposing now that the operators at stations Nos. 1 and 4t desire toemploy the secret circuitsystem and they have placed themselves incommunication as before described by lifting their respective receiversoff the hook arms J and turning the arms B into contact with the springs0. and 0' respectively both of from which the currentspass to thetelephone B through wire S. The currents then in the which in thisinstance must be so adjusted, they each then raise the lever arm M atthe respective stations. The telephone currents then pass between thetwo stations Nos. 1 and 4 as follows, assuming that they first pass fromthe telephone R throughv the wire R. I

They pass at No. 1 station through plate G and through the springcontacts G and L which are pressed together by hook arm J, through wireL, contact I disk and disk-arm B B contact 0 and leave No. 1 station andpass to No. 4 station by wire P At this station No. 4 the currents passthrough plate 0 wire 0 spring N plate M spring N wire 0 plate P reversemanner pass from the telephone R to telephone R by way of the followingof the No. 4 station connections viz:plate G,

spring contacts G and L, wire L, contact I disk and disk-arm B B contact0'. rents then pass from No. 4 station to No. 1 station by the wire Pand at No. 1 station they pass to the telephone B through the followingof the No. 1 station connections viz:

plate 0 wire 0 spring N plate M spring N wire 0 plate P and wire S. Ifthe leverarms M of any two stations in communication are not raised aslast described then the secret circuit system is not brought intooperation and the conversation carried on between these two stations mayas in the arrangement which it will pass through the followingconnections of said station No. 2 in the order in The cur- 1 which theyare named vim-plate G, contacts G and L, wire L, contactI disk anddiskarrn B 13 contact 0 The current thus leaving station No. 2 will beconducted to station N0. 6 through Wire P and will then pass through thefollowing connections of station No. 6 in the order in which they arenamed viz:plate 0 wire 0 spring N, plate 0, wire 0 pivot J, hook arm Jand contact G, plate G, wire R, telephone R wire S, plate P, wire 0spring N, plate 0, wire 0 plate E, wire U to earth, through which thecurrent passes and returns to telephone R through the followingconnections of station No. 2 viz:wire U, plate E, wire 0 plate 0,contact spring N, wire 0 plate P and wire S. The other alternative opento the passage of currents between No. 2 station to No. 6 is first fromtelephone B through wire Rand through the following of the No. 2stations connections viz:-plate G, contact G, hook arm J, pivot J, wire0 plate 0, contact spring N, wire 0 plate 0 wire I? which conducts thecurrents to contact plate 0 at No. 6 station. At this station thecurrents thus conducted pass through the following of theNo. 6 stationconnections viz:-spring contact 0 disk-arm and disk B B contact I, wireL contacts L and G, plate G, wire R, telephone R wire S, plate P, Wire 0spring contact N, plate 0, wire 0 plate E and wire U to earth with whichthe telephone R is also connected as before explained.

The before described apparatus instead of being constructed with anadjustable arm B for making contact with the distant line termini whichhowever is the preferred arrangement, may be provided with an adjustableplug for this purpose, and in other respects the invention may bemodified without departing from the spirit of the invention; forexample, if desired the contacts F G and L and the hook arm J may bemounted on a block or frame independent of the block A upon which aremounted the switch contacts 0 &c. and parts co-operating therewith.

For the sake of facilitating the understanding of the invention nomention is herein previously made to the use of microphones inconjunction with the before described apparatus, when such however areused an extra contact as usual is required for closing .the circuit whenthe receiver is off the hook. In cases where no microphone is used onebattery may if desired be arranged to ring all the bells in the system.

I claim 1. A telephonic system embodying home, tel ephone and bell linesswitches controlling the communicating home and telephone lines but notthe bell line, telephone hooks and contacts moved by said hookscontrolling the home line, the telephone line and bell line saidcontacts being so arranged relative to the hook that when the hook isdepressed, the bell circuit is established and the circuits of the homeline and telephone are broken and when elevated said circuits areestablished, substantially as described, whereby the necessity ofsetting the switch after a conversation is avoided.

2. In a telephonic installation or intercomniunication system in whicheach station has a direct line to each other station and may be placedin communication with any of the other stations without an intermediarythe combination with a switch board at each station of acontactpermanently connected with the telephone a movable hook arm and anothercontact which may be connected through the switch with any of thedistant lines both of the contacts being out of contact with each otherand with the home line when the receiver is on the hook arm and both ofwhich when the receiver is moved from the hook arm make contact witheach other and with the line wire substantially as described.

3. In a telephonic installation the combination in the same switchboard' and with the movable hook arm thereof of a contact perm anentlyconnected with the telephone and another contact which may be connectedthrough the switch with any of the distant lines connected to it both ofthe contacts being out of contact with each other and with the home linewhen the receiver is on the hook arm and both of which when the receiveris removed from the hook arm make contact wit-h each other and with theline wire substantially as described.

4. In an intercommunication telephonic systerm the combination with ahook arm such as J connected with the line-wire of a contact such as Lconnected to the switch used for connecting with different lines andanother contact such as G connected to the telephone so arranged .thatboth contacts are out of contact with the hook J and with each otherwhen the receiver is on its hook and both when the receiver is removedfrom the hook arm make contact with each other and with the hook arm .Isubstantially as described.

5. In a telephonic installation the combination with a disk or centralspindle having an arm and surrounded by a number of spring contactsconstituting the termini of the distant lines and with either of whichthe arm may make contact, a contact for connecting with the home lineand telephone and with which the disk is normally in contact and abattery contact with which the disk is normally out of contact but maybe pushed against it substantially as described.

6. In an electrical switch for connecting the home telephone line witheither of a number of other lines, the combination with alongitudinally'movable spindle B having a projection B a series ofsprings in circuit with the distant lines and in position to be engagedby said projection, of a home line contact in position to establish thecircuit when the spindle is in normal position and a battery contact inposition to establish the battery circuit when the spindle is movedlongitudinally, whereby the home line is broken and battery sent to thedistant line by moving the spindle; substantially as described.

7. In a telephonic installation, the combination with a switch boardhaving a movable hook arm J and rotary and longitudinally movable disk Bprovided with acontact arm B of aseries of spring contacts 0, &c., inposition to contact with arm B a spring contact D for the batterycircuit out of contact with said disk when the latter is in normalposition and in contact therewith when the disk is moved longitudinallyand contact F completing the bell circuit when the hook lever isdepressed, and contacts G and L completing the line circuits when thehook lever is raised; substantially as described.

8. In a telephone installation, the combination with a switch board orblock Ahaving a rotary and longitudinally movable spindle B carrying adisk B and arm B and the series of spring contacts a, &c., of thecontact D' controlling the battery circuit and contact I controlling thehome circuit and contacting respectively with the disk'to complete theircircuits when said spindle is at opposite extremes of its longitudinalmovement; substantially as described.

9. In a telephonic system the combination withaswitch'board or block Aof a three armed lever, one arm J hooked for the suspension therefrom ofthe receiver, another arm making contact with the home-bell connection Fand being out of contact with the home telephone when the receiver is onthe hook and vice versa and the third arm shifting the contact disk Band through it making contact for itself and the disk with the batterysubstantially as described and illustrated in the accompanying drawings.

10. In an intercommunication system .of telephony, the combination witha series of stations each having a home line'wire terminating incontacts at each of the other stations a switch at each stationforconnecting any one of said terminal contacts with the telephone ofthat station, a ground connection for the telephone of each station,switches in such ground connections and contacts for establishingconnection between the telephones of each station and its home line inlieu of the ground connection, whereby a complete metallic circuit maybe established between any two stations to the exclusion of the others,substantially as described.

11. In atelephone system, the combination with a series ofstations withdouble line wires between each two stations, a plate 0 in each stationconnected with ground, a plate 0 in each station, connected with oneterminal of the telephone and the terminal of one line wire, a contactN'connectingthe terminal of the other line wire with the plate 0 and acontact N connecting the other terminal of the telephone with plate 0,of acontact lever co-operating with the contacts N N to interrupt theirconnection with plates 0 O and IIO the other to the home telephone and alever M M M substantially as described and illustrated in theaccompanying drawings.

In testimony whereof I have hereto set my I 5 hand in the presence ofthe two subscribing witnesses.

THOMAS BEAVAN SLOPER.

Witnesses:

HARRY B. BRIDGE, CHARLES E. Ross

